The widow of murdered solicitor Pat Finucane has been granted permission to take her bid for a public inquiry into his death to the UK's highest court.

The Belfast lawyer, 39, was shot dead at his house in North Belfast in 1989 by loyalists in an attack found to involve collusion with the state.

Former Prime Minister David Cameron decided not to hold a public inquiry but instead ordered an investigation by a senior lawyer, a decision which will be at the heart of the Supreme Court hearing.

The review by Sir Desmond de Silva QC, a former UN war crimes prosecutor, concluded there was "no overarching state conspiracy" in his death, but found "shocking" levels of state collusion involving the army, police and MI5.

Peter Madden of Madden & Finucane Solicitors said: "This afternoon we have been notified that a committee of Supreme Court justices have granted Geraldine Finucane permission to appeal against the decision of the Court of Appeal that David Cameron was justified in reneging on a commitment given to Pat's family, and to the Irish government, that it would hold a public inquiry into the circumstances of Pat's murder."

The Finucane family has fought a lengthy battle for a public inquiry through the courts. Mrs Finucane has described the De Silva report as a "whitewash".

Her lawyer added: "The only way that the full truth about Pat's murder can be firmly established, and the extent to which a policy of extra-judicial assassination of which Pat was a victim was authorised by government is by a full transparent public inquiry where witnesses and documents are subject to intense scrutiny.

"We will seek to persuade the Supreme Court at the hearing of this appeal that David Cameron acted unlawfully in refusing a public inquiry and that the Court should quash his decision."